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P. DE LANGE.,

SYSTEM OF WIRELESS TELEGRAPHY AND TELEPHONY, APPLICATION FILED MAR. 23.1915.

1,317,435, PatentedSept. 30, 191a ll/122M246: I

I 1 I fizz/077,507.-

Pz'eZer deLm e UNITED STATES PATENT OFFICE.

PIETER DE LANGE, OF UTRECHT, NETHERLANDS, ASSIGNOR, BY MESNE ASSIGNMENTS,

TO AMERICAN THERMOPHONE COMPANY, OF BOSTON, MASSACHUSETTS, A CORPO- RATION OF MASSACHUSETTS.

Specification of Letters Patent.

Patented Sept. 30, 1919.

Application filed. March 23, 1915. Serial No. 16,431.

ful System of Wireless Telegraphy and Telephony, of which the following is a specification.

My invention relates to improvements in a system of wireless transmission of electric waves for the purposes of telegraphy and telephony. My invention is based on the discovery, that when using in wireless telegraphy or telephony a receiver in the form of a thermic telephone of any known construction the detector which in systems used hitherto is provided between the aerial conductor and the telephone, can be omitted.

Experiments have shown, that the function of the detector can be fulfilled by the thermic which is thus used simultaneously as receiver. This property is robably based on the fact that a thermic te ephone has no induction whatever. Furthermore, I have found that the condenser which in the usual wireless arrangement is connected in shunt to the telephone and the battery which is included in the shunt circuit, can be omitted, when a thermic telephone is used. Thereby the system for wireless transmission of electric waves is made exceedingly simple and the operation of the apparatus is made very easy. In this way various disadvantages are avoided which are inherent to the systems of wireless telegraphy and telephony operating with a detector and a condenser.

For the purposeof explaining my inven tion an example embodying the same has been shown in the accompanying drawing, in which a diagrammatical view of my improved apparatus is shown. I

Referring to the drawing, the aerial conductor a of the receiving station is connected with a thermic telephone 1) which is preferably grounded through an induction coil 0 provided with means for regulating the ac tion thereof.

I have discovered, that the reproduction of the sound by the thermic telephone is greatly improved within certain limits by increasing the inner resistance of the telephone.

From the foregoing description it will be understood, that my improved system is simple in construction and requires but little space. Besides this the operation of the system is very simple. 'For these reasons my improved system is particularly suitable for use in wireless telegraphy and telephony on battle fields and on board of ships.

I claim as my invention:

1. The herein described system of wireless reception of electric waves for the purposes of telegraphy and telephony, comprising an aerial conductor and a receiver in the form of a thermic telephone having simultaneously the function of a detector.

2. The herein described system of wireless reception of electric waves for the purposes of telegraphy and telephony, which consists of an aerial conductor, and a grounded receiver in the form of a thermic telephone connected therewith and having simultaneously the function of a detector.

3. The herein described system of wireless reception of electric waves for the purposes of telegraphy and telephony, which consists of an aerial conductor, and a receiver in the form of a thermic telephone of high inner resistance connected therewith and having simultaneously the func tion of a detector.

4. The herein described system of wireless reception of electric waves for the purposes of telegraphy and telephony, which consists of an aerial conductor, a grounded receiver in the form of a thermic telephone connected therewith and having simultaneously the function of a detector, and an induction coil included in the circuit of said thermic telephone.

5. The herein described system of wireless reception of electric waves for the purposes of telegraphy and telephony, which consists of an aerial conductor, a grounded receiver in the form of a thermic telephone connected therewith and having simultaneously the function of a detector, an induction coil included in the circuit of said thermic telephone, and means for regulating the action of said induction coil.

In testimony whereof, I have signed this specification in the presence of two subscrib ing witnesses.

PIETER DE LANGE. Witnesses:

D. KLEYN, R. A. VAN LYNDE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of latent: Washington, D. 0. 

